Exercising for Two?

British long distance runner Paula Radcliffe trained until the day before the birth of her daughter, in January 2007. Just 10 months later, she went on to win the New York City Marathon for the first time.

Now, I certainly wasn't running marathons when I was pregnant—or before! Or since!—but I must say that I did feel as fit and healthy as I ever have during those nine months. I took long walks every day up until the evening I went into labor, did prenatal yoga once or twice a week, and had tennis lessons well into my third trimester (until my instructor gently suggested that I retire my racket until my "balance reappeared").

Forget barefoot and expecting. Women with normal, healthy pregnancies can and should get at least 30 minutes of moderate exercise on most, if not all, days of the week, according to the latest recommendations from the American College of Obstetricians and Gynecologists. And that's even if you've been a couch potato up until this point.

Very Personal Training

The one workout that benefits every pregnant woman? Kegel exercises, which strengthen the muscles of the pelvic floor that help support the urethra, bladder, uterus, and rectum. Fleming says that these quick and easy exercises should be done daily, in order to ease pushing during labor, help heal episiotomy or tearing wounds, and prevent postpartum urinary incontinence, among other benefits. Here's one version to try:

Squeeze the pelvic-floor muscles, as if you're trying to stop the flow of urine (but not during the act of urinating).

Tighten and relax these muscles over and over, holding for 10 seconds, then releasing. Repeat 15 to 25 times, four to five times a day.

"There's no question that there's no harm to prenatal exercise, and there are some clear benefits, as well," says Louis Curet, MD, professor emeritus of obstetrics and gynecology at the University of New Mexico and a practicing obstetrician. He notes that studies have shown that staying active reduces emotional stress during pregnancy and can lead to both shorter labor and fewer complications. Prenatal exercise can also keep excessive weight gain in check; ease common aches and pains like back problems, constipation, and incontinence; and help prevent gestational diabetes and hypertension. For those who have preexisting or gestational diabetes, it may help lower or maintain healthy blood glucose levels. Staying fit while expecting has also been linked to a quicker postpartum recovery—and a faster return to your pre-baby weight. There may be cardiovascular benefits for your baby, too: A new study presented at the annual meeting of the American Physiological Society in April found that the fetuses of mothers who exercised had significantly lower heart rates than those of mothers who were inactive.

While it's important to consult with your doctor before starting any prenatal exercise plan, you can likely continue—or start—a range of fitness activities during pregnancy, including swimming, stationary biking, aerobics, Pilates, yoga, and even running, if you're already a faithful devotee. (And there are now loads of targeted books and DVDs that will help you get started, if you need a push in the right direction.) If you've been less active to this point, try a stroll around the neighborhood first. "Walking is perfect for pregnant women because it is a very forgiving activity," says Mark Fenton, coauthor of Walking Through Pregnancy and Beyond. "Impact forces rarely exceed your own body weight, and are applied very gradually and smoothly. [There's] no abrupt banging or high impact as in running and some aerobics." He also points out that walking can reduce the likelihood or discomfort of varicose veins, as well as swollen feet and legs.

Regardless of what type of cardiovascular workout you opt for, it's key to keep your prenatal workout routine balanced, says Tracy Gaudet, MD, executive director of integrative medicine at the Duke University School of Medicine and author of Body, Soul and Baby: A Doctor's Guide to the Complete Pregnancy Experience, from Preconception to Postpartum. She recommends some form of strength training, at least three times a week on nonconsecutive days. "It's good for your general health, improving muscle tone and bone strength, but may also help prevent the normal aches and pains of pregnancy, like back problems," she explains, adding that using light weights with moderate repetitions will help you maintain flexibility and muscle tone while minimizing the risk of injury.

When it comes to what to avoid, "use common sense," counsels Curet, who advises patients to forget about any activity with a risk of falling or abdominal injury, such as mountain biking, skiing, and horseback riding, as well as scuba diving. It's essential to stop moving and contact your doctor immediately if you notice any unusual symptoms, including vaginal bleeding, cramping, excessive nausea, lightheadedness, or extreme headaches. "Listen to your body: If something feels weird, stop," adds certified personal trainer Sue Fleming, author of Buff Moms-to-Be: The Complete Guide to Fitness for Expectant Mothers and Buff Moms, who typically recommends that her pregnant clients keep their heart rates at or below 140 and limit workouts to under an hour, for safety's sake. She adds that pregnant women should never exercise to the point of exhaustion. "This is not the time to go crazy, but that doesn't mean you can't remain active," says Fleming. "With rare exceptions, every woman can—and should—stay as fit during pregnancy" as they were before. Not only will you feel great, but you'll be setting a fantastic, active example for your new child, too.

Carolyn Butler has written for the Washington Post and the New York Times, among other publications.

A Mom's Plan to Buffness

While every expectant mother will have a different experience, personal trainer Sue Fleming suggests balancing a cardio workout like walking or swimming with a simple strength-training program, like the one outlined in her book, Buff Moms-to-Be: The Complete Guide to Fitness for Expectant Mothers, which also has a companion DVD. To start, try doing some basic stretching along with these three exercises, two to three times a week (with the noted modifications as you get into your third trimester). All you need is a firm fitness ball that's appropriate for your height; a pair of light weights is optional. This quick, easy, but well-rounded routine will help you stay fit and healthy throughout your pregnancy and prepare you for all the heavy lifting to come, once that little bundle of joy arrives—not to mention ease the hard work of getting your pre-baby body back!

Push-Ups with Ball

From a kneeling position, pull a fitness ball in toward your quads, drape your torso over it, and put your hands on the floor in front of it. Tighten abs and walk hands forward until your hips are in front of the ball and your back is flat. Your feet will not be on the floor. Continue to tighten your abs, letting the ball roll slightly under you towards your knees. Hold this position.

Slowly, to the count of four, bend your elbows and lower your chest to the floor. Don't place your hands too wide or too narrow, and don't lead with your hips. Inhale as you lower your chest to the ball; exhale as you return to the starting position.

You can increase the intensity of the exercise by placing the ball closer to your feet. Placing the ball more toward the midline of your body will make the exercise easier.

Do two sets of eight to 10 repetitions. Recommended for first and second trimesters, although women in their third trimesters can bring the ball up toward the midline to make the exercise less strenuous.

Ball Roll

Kneeling, place your forearms and hands (clenched together) on a fitness ball. Your hips should be in line with your knees. Keeping your abdominals tight and back straight, roll forward about 12 inches, or until you feel a tightening in your abdominals. Pause, then slowly roll back to starting position. Make sure to maintain control when doing this exercise so the ball doesn't roll away.

Do two sets of eight to 10 repetitions.

Wall Sits with Ball

Place a fitness ball between your lower back and a wall. If you want, hold a dumbbell in each hand, arms hanging by your side, palms facing in. (As you progress in your pregnancy and your body weight increases, dumbbells may not be necessary.) Keeping your lower back against the ball, walk your feet forward about 24 inches, keeping them shoulder-width apart. Keeping back straight, shoulders back, and chest out, to a count of four, slowly bend your knees to a 90-degree angle. Your knees should stay over your toes. Pushing through the heels, slowly return to starting position to a count of four.

Do two sets of 10 repetitions.

Your Prenatal Exercise Plan

Tracy Gaudet, MD, author of Body, Soul and Baby: A Doctor's Guide to the Complete Pregnancy Experience, from Preconception to Postpartum offers some practical tips for a safe—and successful—prenatal exercise plan:

Make sure your movement choices are balanced. Aerobic exercise, stretching, and strengthening should all have a place in your routine.

Review your exercise wardrobe. You'll be able to do more if you're comfortable. You may find that you're hotter than before, so removable layers can be useful. You may also need a more supportive athletic bra and more stretchy, elastic waistbands as pregnancy progresses. Check the fit of your shoes periodically, too, since pregnancy can make them wider.

Don't be afraid to work up a sweat. There's no evidence that the increase in body temperature from hard exercise places the fetus in danger.

Monitor yourself as you go. Check during any workout, but especially an aerobic one, to see how your body is doing. You have less oxygen available for aerobic exertion during pregnancy, so you may need to modify the intensity of your workouts. Stop when you're tired, and never exercise to exhaustion. A good rule of thumb: Be sure you can talk while exercising.

Drink water. Pregnancy limits the capacity of your bladder, so you may need to hydrate more often and urinate more often than usual.

Always avoid positioning yourself flat on your back. This compresses a vital vein (the inferior vena cava, which carries all of the blood from the lower body to the heart) from about the fourth month on, and it's best to avoid the habit from the start.

Warm up before workouts, and cool down afterward. An exercise basic, whether you're pregnant or not.